Problem with array modifier, incorrect orientation and deformation
You need to apply the scale of your bezier circle with CtrlA. Once done don't forget to correct the vertices radius, given that applying scale will change the vertices radius up to the former scale value (go into Edit mode, select the bezier vertices and in the N panel bring back the Mean Radius to 1):

But anyway, Array + Curve modifiers always deform your object at least a bit, if you don't want it to be deformed you need to use another method like instances on vertices or particles. In the latest versions the Geometry Node Editor is even more flexible.